Cylinder-lining for steam-turbines.



F. HODGKINSON.

CYLINDER LINING FOR STEAM TURBINES.

APPLIOATION FILED JUNE 12, 1908.

Fliiii ah m & ATTORNEY IN FACT.

l :1 I I l x k I 'Y 1 W H i 1 I L I F :1

INVENTOR Patented June 6 i if- I B t ii- WITNESSES.-

CYLINDER-LINING FOR STEAM-TURBIN ES.

Specification of Letters Patent. Application filed June 12,1908.

Patented June 6, 1911. Serial No. 438,165.

I '0 all whom it may concern:

Be it known that I, FRANCIS I-IoDcKIN- soN, a subject of the King of Great Britain and Ireland, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Cylinder-Linings for Steam-Turbines, of which the following is a specification.

This invention relates to blading means for elastic fluid turbines and also to means for protecting the working elements of the turbine from the corrosive and erosive action of the motive fluid.

An object of this invention is the production of simple and effective means for blading a turbine in connection with means for effectively securing a protective covering for the blade-carrying element in place on the element.

A further object is the production of a simple and effective means for assembling the blades in segmental strips and for rendering the operation of renewing blades in a turbine a simple matter.

The erosive and corrosive action encountered in turbines may result from chemical impurities in the boiler feed water, such, for instance, as organic or inorganic acids, or it may result from the corrosive action of disstilled water, that is, the water of condensation, and the erosive action of the motive fluid and the water of condensation in their passage through the turbine. Whatever the cause, the fact remains that the exposed surfaces of the working elements are at times and under certain conditions badly pitted and corroded. The cast iron casing is usually more actively attacked, but the rotor element is sometimes attacked and I, therefore, contemplate providing a protective covering which may be eifectively secured to both the stationary casing and the rotating element.

In the drawings accompanying this application and forming a part thereof: Figure l is a fragmental section taken longitudinally of the turbine of a rotatable blade carrying element; Fig. 2 is a partial section taken along the line A-B of Fig. 1; Fig. 3 is a plan view of the rotatable blade-carrying element of a turbine provided with blades and a protective covering secured in place in accordance with my invention; Fig.

4 is a fragmental section, taken longitudinally of the turbine, of a stationary bladecarrying element; and, Fig. 5 is a perspective view of a spacing piece which forms a detail of my invention.

My invention contemplates assembling the blades and spacing pieces, which are located between the bases or roots of the blades, into segmental strips, and providing means for securing both the blade strips and a protective strip for the blade-carrying element to that element.

The blade-carrying element 6 of the turbine is provided with a plurality of undercut blademounting slots 7 in which blades 8 and intermediate spacing pieces 9 are as sembled. Each blade is provided near its base with a hole 10 which extends transverscly through it and each spacing piece 9 is provided with a hole 11 which extends transversely through it and which is so located within the piece as to register \\.=;1 the hole 10 of an adjacent blade 8 when the blades and spacing pieces are assembled in a segmental strip.

The blades 8 and spacing pieces 9 are, before they are introduced into the blade carrying slot 7, assembled into segmental strips or sections by threading a number of alternately-arranged blades and spacing pieces onto a binder wire 12 which is adapted to be threaded through the holes 10 and 11 of respective blades and pieces. Any suit able method may be employed for assembling the blades and pieces on the wire and after they are in place the ends of the wire may be riveted over to secure them together and to form a rigid segmental blade strip.

The outer or free ends of the blades are provided with comma-shaped holes 13 through which a binding wire 14 of commashaped cross-section is adapted to extend. The binding wire is secured in place by shearing on each side of each blade and bending over between adjacent blades a longitudinally-extending rib 15 which is formed integrally with the wire 14. The bent-over portion of the rib forms spacing pieces which are secured to the man body portion of the wire 14 and which positively lock the outer ends of the blades permanently in their relative positions. The main body portion of the wire acts as a binder for the outer or free ends of the blades.

After the blades and spacing pieces have 1 troduced into the blade-mounting slots in been assembled in the segmental strips, the such a way that the inclined faces of the strips are secured in the blade-mounting spacing pieces 9, assembled in one strip, conslots by means of cooperating wedges 19 tact with one inclined wall of the slots. which are driven home in pairs, one wedge The blade strips are then secured in place beside the other, between the segmental by inserting the compound tapered wedges strips and one wall of the mounting slot. 19 between the vertical wall of the strip and The lateral face 16 of each spacing piece 9 the other undercut wall of the slot. Each is so inclined relative to the top and bottom protective strip is then looked in place by faces of the piece as to conform to the incausing the beveled edge 22 to abut against clination of the undercut walls of the slot. and engage with the longitudinally-extend- The other lateral face of each piece extends ing and overhanging lugs formed on one at right angles to the top and bottom faces. segmental strip by the cooperating lugs 21 The spacing pieces, when assembled with of each of thecomponent spacing pieces 9. the blades into the blade strips, produce a The protective strip 23 is of suflicient width base strip with one lateral face inclined and to cover the portion of the peripheral face the other normal to the peripheral faces of of the blade-carrying element between adjathe strip. The wedges 19 are preferably cent slots and also the wedges utilized in compoun tapered wedges and are so consecuring the blades into one blade-mounting structed that when driven home the two slot. The strip is secured in place by calking or peening over the outwardly-projecting lugs of the spacing piece 9 so that it engages the edges 25 and secures the. strip in place on the blade-carrying element.

I have utilized the word blade throughout this specification and in the claims in the broadest sense, that is, to mean either the rotating or stationary blades or buckets of a turbine, and the term blade-carrying element has been employed in the same way, that is, to mean either the rotative or stationary blade or bucket carrying element of a turbine.

In accordance with the provisions of the patent statutes, I have described the principle of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

\Vhat I claim is 1. In combination in a turbine, a bladecarrying element provided with a blademounting slot, alternately arranged blades and spacing pieces located in said slot, means for assembling said blades and pieces in segmental rings and for securing the rings into the slots of said element, a protective strip for said element, and means formed integrally with each spacing piece and located on each side of each piece for securing said strip in place.

2. In combination in a turbine, a bladecarrying element provided with mounting slots, a segmental blade-mounting ring comprising alternately arranged blades and spacing pieces, means for securing said ring in said slot, a protective covering for v said element and lugs provided on each side of each ofsaid spacing pieces for securing said strip in place.

3. In a turbine, a blade-carrying element provided with a slot, blade-holding means in said slot, a protective covering for said wedges of each pair conjointly form a wedge-shaped key which efiectively secures the blade strip into the blade-mounting slot and which is prevented by its shape and the shape of its component wedges from being dislodged from the slot by centrifugal or any other dislodging force.

The segmental strips are of such length that two or more are required to make up an annular row of blades and they are so arranged at their ends that they may be inserted into the blade-mounting slots 7 end to end without destroying the regular spacing of the blades. A number of pairs of compound wedges are employed to secure each segmental strip in a slot. The wedges are preferably so spaced within the slots that the component wedges of each pair abut one against the other. Such an arrangement prevents the component wedges of each pair from moving longitudinally and from therebybecoming dislodged from, the slot, it being understood that some suitable. means is employed to secure the wedges of the first and last pair introduced into the slot against longitudinal motion.

Each spacing piece 9 is provided with a laterally-projecting lug 21, which is located on the same side of the piece as the face 16 and which extends beyond the walls of the blade-mounting slot and which is adapted to engage a beveled edge 22 of a protective strip 23 which is located between adjacent rows of blades secured in place on the bladecarrying element. Each spacing piece is provided at its other lateral face with an outwardly-projecting flange 24; which extends beyond the walls of the blade-mounting slot in the direction of the face 17 and which is adapted to be forced into an engagement with a beveled edge 25v of the protective strip 23' by being peened or calked over.

In securing the blades to the blade-carrying elements, the segmental strips are inbladeelement, means on one side of the bladeholding means overlying an edge of one protecting element and a bendable portion of the opposite side of the bladesecuring means to be peened over the edge of a protecting covering.

4. In combination with a blade-carrying element of a turbine provided with a plurality of blade-mounting slots, alternately arranged blades and spacing pieces secured in said slot, a protective strip for said element, means formed integrally with each piece and adapted to engage one edge of said strip, and means formed integrally with each piece and adapted to be peened over to engage an edge of a protective strip.

5. In combination with a blade-carrying element provided with a plurality of bladelnounting slots, alternately arranged blades and spacing pieces located in said slot, a protective strip for said element and a lug formed integrally with each spacing piece and adapted to be peened over to engage and secure in place said strip;

6. In combination with a blade-carrying element, blades comprised in a row, a spacing piece located between adjacent blades and provided on one side with a laterallyprojecting lug and on the other side with a projecting lug adapted to be peened over.

7. A built-up structure for turbine blading including blades and spacing pieces secured together, one blade-spacing piece comprising a body portion having an overhanging lip at one edge and a bendable lip at the opposite edge in combination with a protective strip to be engaged by one of said li s.

8. A blade-spacing block for turbines having a laterally projecting rigid portion at one edge and an upstanding portion at the opposite edge, the upstanding portion being adapted to be bent into an approximately lateral plane.

9. A spacing block for turbine blades of 4 wedge form having a rigid lateral projecting portion and a flexible upstanding portion.

10. A spacing block for turbine blades having a hole therethrough, a rigid lateral projecting portion and a flexible upstanding portion.

11. In a turbine, an element= provided with a slot, spacing pieces for blades one be bent over the opposite edge of the slot and the other edge of which is adapted to be bent over the opposite edge of the slot and protective covering strips to be engaged by the edges of the spacing pieces.

In testimony whereof, I have hereunto subscribed my name this 4th day of June,

FRANCIS HODGKIN SON. Witnesses:

CHARLES W. MoGi-mn, E. NV. MoOALLIs'rnR.

Copies of this patent may be obtained for five cents each, by addressing the Washington, D. 0.

Commissioner of Patents, 

